A ladder cable tray is a structural systems design to organize and support cable in commercial or industrial settings. The vertical cable ladders STL, STM and STIC meet the exact specifications and definitions of DIN 4102 Part 12 of November 1998, such as height of the cableladder / tray, width of the cable ladder/ tray, proportion of holes in the cable tray, distance between rungs of the cable ladder, material. Answer: No. NEC section 300-8 does not permit any tube, pipe, or equal for water, air gas, drainage, steam, or any service other than electrical in raceways or cable trays containing. A Vertical Cable Tray is a specialized support system designed to carry electrical and data cables securely in a vertical or riser direction. This tray has two rungs running parallel to each other, and are connected by rungs – looking like a ladder.